In cyberspace, the emergence and increasing importance of search engine prompts numerous evaluation studies in regard to its effectiveness. Based on a user-oriented perspective, the paper is aimed to derive functional requirements of search engines rooted in Herzberg’s Two Factor Theory. A survey, with 758 valid participants, was conducted to investigate the impacts of various functions of search engines on user’s behavior. The empirical results showed that user’s expectations of functional requirements are distinguished into two categories: motivation factors and hygiene factors. Hygiene factors of search engine “attract” users to try a search engine in the first place, but it is the motivation factors that “retain” users to continue using the same search engine.